I'd have to make a few assumptions, first.
- 3-5 players is my ideal group size. I'd probably not really enjoy a solo or even duo game, although I could pull it off in a pinch. More than 5 and it starts to get too hairy trying to keep track of everyone in the group. It's just not as much fun for anyone anymore.
- This would be a potentially rather dark game with PCs that may skirt the line, on occasion, between anti-hero and actual villain. At least, I've seemed to capture that vibe (whether because of something I'm doing, or just because of who I've played with) in the past, and I can run with it. In fact, I rather quite enjoy it. That said; dark is relative. No creepy, pervy stuff. But this is definitely a "hard PG-13" game, I think.
- Characters may be a bit shady, and if not, they'll certainly have to dip their hands in some pretty shady business. I said long ago, and I borrowed this verbiage more or less from Privateer Press's Five Fingers book, but it applies equally well to anything I run; there are three themes and most campaign-length games will alternate back and forth between them: crime and skulduggery, political intrigue, and horror.
- As I say in the actual text of FANTASY HACK itself, I make no presumptions of a "balanced party"—in fact, I think assuming that there will be one and penalizing players, either passively or overtly, for not creating one, is a passive aggressive dick move as a GM. Your job is to bring a campaign for the characters you've got. As a corollary, I also make no assumptions that the party works well together. I tend to enjoy the game most when they don't actually; when they're on the verge of screwing each other up royally rather than bringing A-game tactics and playing like a well-oiled machine.
All that said; how would I actually run the game? Well... time for yet another list.
- Bring something like Chris Perkins' 3/24/2011 column "Point of Origin" for the characters to latch on to, if they so choose. Along with the character ties rule in chargen, this means that I need players to make characters as the first "half" of the first session, but they'll be nicely tied to both the setting and to each other when we're ready to start.
- I'd have a bit of a minor railroad at the start. In my experience, players rarely are capable of intelligently taking initiative for a session or two until they've managed to get their bearings in the game. Give them something obvious to work with right off the bat. This would be directly related to the early CULT OF UNDEATH events.
- Create two other plots. I don't mean plot in the sense of novel or screenplay writing; I mean plot in the sense of "major impending problem that will be unable to be ignored. Clues point directly to it, and mitigating actions can be taken, which is where the PCs come in." Or, "NPCs causing big trouble that will collide with the probable course of the PCs." But they provide the solutions; you just provide the problem. For instance: the CULT OF UNDEATH problem is based on the secretive Black Path trying to steal one of old professor Alpon's amulets that can be used, along with human sacrifice (and of course, Alpon's daughter for various reasons is the preferred sacrifice) to open the vault under which Tarush is kept imprisoned under Grozavest. Other ones might be: Jann pirates have grown increasingly bold on the coastal cities, and have razed some completely to the waterline. Far from being a nuisance and mere raiders, they are now migrating to Timischburg, will burn Grozavest itself to the ground, and kill or enslave the inhabitants as they attempt to establish their own nation on the ruins of the one that stands here today. What is prompting them to move en masse from their homelands on the southern shores, anyway? Or, daemonologist heretics from the northwest are gradually loosening the bonds which hold a number of powerful daemons at bay outside of the world as we know it. At first, only small daemons are able to slip through the tiny cracks, creating havoc in the north, but it's gradually going to get worse until a powerful Daemon Prince is able to come, which will bring about apocalyptic levels of devastation and suffering. These are kinda cliche, but that's OK (it ain't broke) so put a twist on them.
- These other plots will eventually get more development. Clues to what's happening will start to pop up early on, and by the time we're three or four sessions in, the PCs should have all kinds of dangling hooks from which to choose and bite on.
- In addition to this, create a secret mystery or arc related to each character; something that is separate from the big stories, but which is important to the character. Totally cool to work with the players on this; either because they picked an origin that you suggested, or because you're riffing off of an origin that they themselves created. Start throwing clues of this out there too.
- Mix, rinse and spin. You don't need a plan beyond this that stretches more than a session or two. As you dangle clues and hints of things related to all of plots out there, the PCs will go whichever way they choose to go, and you are reacting to their actions rather than the other way around. Create stuff that seems logical and predictable based on their actions. Give them some big wins. Give them pyrrhic victories. Have them wallow occasionally in the agony of defeat. Always make sure that stuff gets complicated, though. Even the big wins will tend to have side effects, and even the worst defeat has a silver lining that can be taken advantage of to claw their way back into... something entertaining.
Anyway, that's the way I'd run this if I were actually running. Which maybe I'll try to do. Like I said recently, my old gaming group is too fragmented, too busy, too far apart—I don't think that's viable anymore. But I've got a store not far that I can trawl for new players, and I can maybe come up with other alternatives too. First I just have to make sure that I'm not too busy to do it...